Kidney disease patients who have slower walking speed on physical performance tests seem to be more burdened by their disease than patients who perform well on lower extremity physical performance tests, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The findings indicate that measuring lower extremity physical performance may capture a complex set of skeletal muscle and neurologic impairments that develop in CKD patients and substantially affect their survival.